Primitive Oribatids of the Palaearctic Region [antikvár]

INTRODUCTIONThis volume is the first pari of the brief characterizations of and identification keys to the Oribatid laxa of the world, dealing with the primitive Oribatids of the Palaearctic Region. The second and third parts, comprising the Picnonotic and Poronotic Oribatids, are in preparation. We are convinced that the time is ripe for a concise survey and a summary of the accumulated knowledge, in order to facilitate further investigations and syntheses.Like every identificatory work of a compilative nature, ours too is confined within certain limits. Since we became acquainted during our studies with only a part of the Palaearctic Oribatida, a number of identification keys had to be based merely on descriptions available in literature. Accordingly, the reliability of this part of the book depends primarily on that of the literature source. It is but natural that descriptions originating from diverse periods, and that the works of scholars occupying various levels of erudition and capability, differ in value. Identifications of older species made by recourse to this book should, thereforein case of any doubtbe regarded as preliminary information only, to be checked by a study of the original diagnoses.Our basic endeavour was the interpretation, as far as possible, of the contributions published by contemporary or previous Oribatidologists. We do not invariably agree with systematists who elaborate an animal group exclusively by the total re-evaluation of type-materials preserved in museums. Any such attempt fails inevitably because, in the case of Oribatid mites, older type-materials are either no more extant or in a very bad slate of preservation; nor is Ihe number of active Oribatidologists sufficient to undertake a work of redescription of this immense scope. We believe, however, that a healthy subdivision of labour has already evolved among the Oribatidologists of the world: some authors, following F. Grandjean's concepts, dedicate their time to very detailed studies of one (or more) species, including also their developmental stages, while others describe the faunas of unexplored regions, and others again investigate the Oribatid faunas of their mother countries. We made every attempt to include in our work the results of all of these projects and thus let the identification keys to the Palaearctic Oribatids reflect the present state of Oribatidology, with all its concurrent advantages and disadvantages.The identification keys contain every hitherto described species (the manuscript was closed in June, 1980) whose diagnosis and/or figure permits separation from every congener. If the available information was here considered as inadequate, we placed the species among the "species inquirendae". Part of these species will probably prove to be synonyms, senior or junior, another part distinct species. The respective decision will probably rest with Oribatidologists who reside in the country of origin of the taxa in question. We are also aware of the fact that despite every precaution in certain cases, for instance in the Phthiracarids, our keys and diagnoses represent the figures and7